<template>
	<view class="scroll-view-container">
		<scroll-view class="left-scroll-view" scroll-y :style="{height: wh + 'px'}">
			<block v-for="(item,i) in cateList" :key="i">
				<view :class="['left-scroll-view-item', active===i?'active':'']" @click="activeChanged(i)">
					{{item.cat_name}}
				</view>
			</block>
		</scroll-view>
		<scroll-view class="right-scroll-view" scroll-y :style="{height: wh + 'px'}" :scroll-top="scrollTop" @scroll="scroll">
			<view class="cate-lv2" v-for="(item2, i2) in cateLevel2" :key="i2">
				<view class="cate-lv2-title">/ {{ item2.cat_name }} /</view>
				<view class="cate-lv3-list">
					<view class="cate-lv3-item" v-for="(item3, i3) in item2.children" :key="i3" @click="gotoGoodsList(item3)">
						<image :src="item3.cat_icon"></image>
						<text>{{ item3.cat_name }}</text>
					</view>
				</view>
			</view>
		</scroll-view>
	</view>
</template>

<script>
	import badgeMix from "@/mixins/tabbar-badge.js";
	export default {
		data() {
			return {
				wh: 0, // window height
				cateList: [],
				active: 0,
				cateLevel2: [],
				scrollTop: 0,
				old: {
					scrollTop: 0
				}

			};
		},
		onLoad() {
			const sysInfo = uni.getSystemInfoSync()
			this.wh = sysInfo.windowHeight
			this.getCateList()
		},
		mixins: [badgeMix],
		methods: {
			async getCateList() {
				// 发起请求
				const {
					data: res
				} = await uni.$http.get("/api/public/v1/categories")
				// 判读是否获取失败
				if (res.meta.status !== 200) return uni.$showMsg()
				this.cateList = res.message
				this.cateLevel2 = res.message[0].children
			},
			activeChanged(i) {
				this.active = i;
				this.cateLevel2 = this.cateList[i].children
				this.scrollTop = this.scrollTop===0?1:0
				// this.goTop()
			},
			scroll(e) {
				this.old.scrollTop = e.detail.scrollTop
			},
			goTop(e) {
				this.scrollTop = this.old.scrollTop
				this.$nextTick(() => {
					this.scrollTop = 0
				});
			},
			gotoGoodsList(item){
				uni.navigateTo({
					url: "/subpkg/goods_list/goods_list?cid=" + item.cat_id
				})
			}
		}

	}
</script>

<style lang="scss">
	.scroll-view-container {
		display: flex;

		.left-scroll-view {
			width: 120px;

			.left-scroll-view-item {
				line-height: 60px;
				background-color: #f7f7f7;
				text-align: center;
				font-size: 12px;

				// 激活项的样式
				&.active {
					background-color: #ffffff;
					position: relative;

					&::before {
						content: " ";
						display: block;
						width: 3px;
						height: 30px;
						background-color: #c00000;
						position: absolute;
						left: 0;
						top: 50%;
						transform: translateY(-50%);
					}
				}
			}
		}

		.right-scroll-view {
			.cate-lv2 {
				.cate-lv2-title {
					font-size: 16px;
					font-weight: bold;
					text-align: center;
					padding: 15px 0;
				}

				.cate-lv3-list {
					display: flex;
					flex-wrap: wrap;

					.cate-lv3-item {
						width: 33.33%;
						margin-bottom: 10px;
						display: flex;
						flex-direction: column;
						align-items: center;

						image {
							width: 60px;
							height: 60px;
						}

						text {
							font-size: 12px;
						}
					}
				}
			}
		}
	}
</style>
